At a site of various types of work, or in a plant, a worker wears a protective cap on the worker's head for protection against the danger caused by a flying or dropping object or against danger of injuries when the worker drops from a height. But if the protective cap is worn for a long time especially in summer or during work accompanied by hard physical labor, the worker's head is steamed by perspiration. As a result, the works become uncomfortable to the worker, and in addition the work efficiency becomes lower.
To provide a protective cap with permeability, there has been disclosed a protective cap made from a net or a meshed and porous material molded into a multi-layered structure with the lacked portions arranged alternately in Japanese Utility Model Laid-Open Publication No.143736/1985. Also the model described in Japanese Utility Model Laid-Open Publication No.7832/1983 has a feature to provide a protective cap with permeability, and further Japanese Utility Model Laid-Open Publication No.94430/1989 discloses an air ventilating device to be set inside safety and protective tools of a working helmet, a vehicle helmet, safety shoes or the like.
However, these protective caps do not have a waterproof feature in rainy weather when worn outdoors.
Japanese Utility Model Publication No.20108/1967 discloses a helmet having permeability and a waterproof feature in rainy weather, but in this model, small holes are provided in a side section of a cap body, so that a flying or dropping object may come inside the cap body through the holes and also the strength is not sufficient, and for the reasons the model can not achieve the essential object of a helmet to protect a wearer's head. Further, when a worker wearing the cap works in a slouching posture, rain water comes into the helmet, so that the helmet can not be worn in rainy weather.